: If you are acquainted with Doug Adams book (and radio show, and movie) The
: Hitchhikers guide to the Universe" you'll recognize that the ultimate
: answer is 42. You may also realize that once you have the answer, you
: still have questions about how to apply your information.

: Same goes with kayak building.

: My suggestion is that you limit the scope of your research. Don't waste time
: looking fo rthe ultimate anything--just deal with the data that you need
: to get out ONE boat which will suit your needs. Even then you may be
: overwhelmed.

: For instance. let us assume that S-glass is indeed somewhat stronger than
: E-glass of the same weight. What do you want to do with that info? Do you
: want to use a thinner and lighter S-glass to replace the specified
: E-glass, and save weight, or do you want to replace your E-glass with the
: wame weight S-glass to get more strength? At this point you would probably
: start looking at cost of materials and their availability, and find that
: it would take 45 days to get the material you need shipped to you, at an
: exhorbitant price. So now you find that you can indeed solve your
: questions, but then can't actually get the materials to build the
: boat--and you are back with new plans, and no work done on the boat.

: Let's break that line of reasoning. Start at the beginning. You want to build
: a baidarka from wood strips. What design have you selected? What materials
: does the designer think the boat should be built from? If the designer has
: specified 4-ounce E-glass then it might be OK to use 4 ounce S-glass, but
: ask the designer if 3-ounce or 2 ounce s-glass would work instead. The
: designer would be the most logical place to start asking specific
: questions about their design. Odds are good that they are alive, have an
: e-mail address, and would be happy to correspond with someone who is
: paying good money to buy a set of their plans.

: You can search the archives of this board for months and get lots of
: opinions. on this. You can delve through Sam McFadden's research and
: statistics (also found in the archives) and get more info. None of it will
: actually help you until you know the answer to one teensy additional
: question, namely: "How much strength do you need?"

: For most small boats you could get all the strength you need with 1/8th inch
: thick (3mm) cedar covered with 2 layers of 2-ounce glass on both sides.
: that might be great for a 15 foot kayak for smooth water and a 100 pound
: paddler, but obviously you aren;t going to build an aircraft carrier from
: the same sized materials. Bigger boats are made from bigger parts. So
: again, we get back to the question of: "What plans you are
: using?" Then we add to that the questions of "How big are
: you?", and "What is the displacement, length, beam etc. of the
: design you are building?" Once we have that info we can start to look
: at the large number of options, and narrow those down to something you can
: work with. Anything beyond that is simply distracting.

: A few pounds. The big savings is in sanding time. If yo do the vacuum bagging
: right you'll have smoother surfaces when you pull off the bag. The
: downside is that you'll spend nearly as much money on peel-ply and
: breather fabrics as you do on your fiberglass. Add in the ocst of a bag 22
: feet long and your just about triple your 'glassing costs. All that ot
: save a quart of resin? Not really worth it to most people.

: This seems to be two parts: bulkheads and seam tapes. The question is
: confuseing so an answer might be meaningless. Please clarify this basic
: issue for me: Do you want the boat to flex or to be stiff? Carbon is great
: for stiffness, but it tends to also be prone to crack rather than flex.
: Kevlar is not used for stiffness. It is good for impact resistance, but
: (weight for weight and size for size) it is not as strong for binding
: seams as glass. The seams are not straight, flat areas, but made up of
: compound curves. Bias-cut glass fabric works nicely for these areas and is
: to be preferred over woven glass tapes. If you use glass for other areas
: of your boat you can frequently cut the strips from the excess fabric.

: The greatest amount of flex is allowed when your bulkheads are perpendicular
: to the centerline of the boat. If the bulkheads are slanted -- which might
: be a nice comfort feature if you plan to use them as foot rests--then you
: increase the area of the hull which is kept rigid by the bracing of the
: bulkhead.

: If you mount the bulkheads tightly to the hull: There are some people who
: believe this creates areas where stresses can develop. If you mount the
: bulkheads slightly away from the hull, using a wide tape of glass fabric,
: you have some ability for the hull to move. If it moves too much, you'll
: crack the resin-soaked tape.

: So, does the design even call for bulkheads? Are you sure you want to put
: your bulkheads close enough to use as footrests, or would you rather have
: a slightly larger cockpit area, and use adjustable footrests so you can
: change your sitting position, or adjsut the seat, to help balance the
: boat, or compensate for wind or loading? Can you use bulkheads made from
: closed-cell foam? Would you be interested in using float bags instead of
: bulkheads? You have a few choices here.

: If you cut away wood from your bulkhead it will be lighter than if it is a
: solid piece. If you then add any resin or glass or kevlar to it then it
: will get heavier than plain wood--not lighter. Your lightest option would
: be to remove the bulkhead completely and replace it with hollowed-out
: hardwood dowels wrapped in a layer of s-glass and polyester resin. Or, use
: a bulkhead frame, which is your bulkhead with the center cut out of it. No
: "X" at all.

: Sorry, never heard of the stuff. If you can point to a site where this is
: offered I'd be interested in reading up on it.

: How would a lower coaming be slower to use? It is easier to trip over higher
: ones. Recessed ones, when built properly, so that the water drains away
: from them, should have enough room around them to fasten your sprayskirt
: just as easily as any other coaming. If you plan to roll this baidarka,
: then the lower the back of the coaming the easier it is on your poor back.
: If you are dealing with lots of waves breaking over the front deck you may
: wish a higher peak to the deck and coaming simply to deflect more water
: away from you.

: Remember that YOU are the one building this boat, and you have the option of
: doing it both ways! Start with building the boat. when you get to the
: deck, leave an opening about 4 to 5 feet long over the cockpit. Glue a
: deck beam under the ends of the strips, and leave a lip, or edge, exposed
: on those deckbeams. Now, build a coaming over the center seciton of the
: deck, stripping from the fore deckbeam to the aft one. When you are done
: you can simply lift up the center of the deck. Make one center with a
: recessed coaming, another with a raised one. You can make a third with a
: mount for oars and a rowing seat, if you wish. Some type of bronze or
: stainless steel bolts can secure your coaming of choice to the deckbeams.
: Unbolt it and change the coaming to suit your fancy. If you want, you can
: leave the wide-open cockpit with no coaming, build up the floor a little,
: and ride in the boat in a manner similar to a sit-on-top kayak.

: 7. I think this is from the double question you posed earlier.

: I hope some of this makes sense to you, and that you will get back to us with
: some more information on your project. The more specific the information
: you have, the better we can focus our opinions and answers. 'Cause you
: don't want universal answers--you want very specific information. And we
: will try to help you there.

: PGJ
Paul , I need a pan galactic gargle blaster after reading your post.! Only kidding , I'm also a big fan of Adams all except the tv series.
Anyway... The desighn will be by Rob Macks who actually suggested 1 of his boats to me in the first place when I posted a question looking for a good rough water boat. I think a North Star with a bit of length and width taken out of it. I'm 6 foot 2 inches and about 180 pounds , so tall and skinny. I know i'm at the lower weight limit for that boat but I think the next size down is a little shorter than I want. I will speak to Rob about volume to payload ratios before starting.
As I like playing in the surf I would use the S glass for strength more than weight reduction.
Bulkheads will probably be Aircraft Birch ply , 3mm only epoxied no glass except the foot brace bulkhead which "may" be 2 layers with a layer of glass to stick them together or carbon kevlar. This bulkhead will be tilted forward for my feet a little and have a foot pump mounted on it , so it needs to be strong and stiff. I will also have 2 others as I do want a day hatch. Helmet , cag food etc will be kept there with a VCP hatch.
I want a stiff hull but don't want it to crack where the bulkheads are which is why i was thinking of atleast having them at an angle so it would still be stiff side to side but not as much up and down.
Coaming speed?? when I launch i usually wait for a wave to pas then dump my bum and quickly get the skirt on before getting the next wave in my lap. I cant have a fully recessed coaming that i would need to feed the skirt down onto. If it takes more than about 2 or 3 seconds to get the skirt seated then thats too long. I do like the thin lip of a glass coaming though and can see the advantages of this. I will try to make the back lower for back deck rolls . My "must do " roll is a sweep over the front deck but I would like to muck around with some other rolls.